Semiconductor devices, integrated circuits, and related manufacturing and packaging techniques and processes are well known. A typical integrated circuit device includes a semiconductor device structure (e.g., a chip) that is packaged with appropriate leads and terminals for connecting the chip circuitry with the next assembly level, such as a circuit board, a carrier substrate, or the like. Some packaging approaches use conductive connection elements, such as solder bumps or copper pillars, that are electrically coupled to respective contact pads of the semiconductor device structure. The conductive connection elements are used to establish physical and electrical connections between the semiconductor device structure and the next level package component. Due to the different thermal expansion (and contraction) properties of the chip versus the package, care must be taken to ensure that the electrical connections remain intact and that thermal expansion and contraction do not damage the chip.
The microelectronic industry strives to create semiconductor devices having increased functionality and compact size. For example, to improve electrical performance of semiconductor devices, materials with low or ultra low dielectric constants (i.e., low-k or ULK materials) are being used as isolating material in multilayer backend stacks. This isolating material is often referred to as interlayer dielectric or ILD material. Unfortunately, the low-k and ULK materials typically used in semiconductor device fabrication are fragile and brittle. Accordingly, using such ILD material presents certain challenges for assembly yield and product reliability. Furthermore, the use of lead-free solder material usually results in much higher stress, due to the higher stiffness of lead-free materials relative to lead-based solder material. Thus, solder bumps formed from stiffer material can transfer more stress (associated with thermal expansion or contraction) to the ILD material of the semiconductor device structure.
Accordingly, it is desirable to have a conductive connection structure or architecture that addresses the limitations and shortcomings of conventional designs. In particular, it is desirable to have a solder bump structure that is suitable for use with lead-free solder material and for chips that use low-k and/or ULK material for the ILD.